diff --git a/ActiveSync/SOGoActiveSyncDispatcher.m b/ActiveSync/SOGoActiveSyncDispatcher.m
index 8c40d520d..0cc588e37 100644
--- a/ActiveSync/SOGoActiveSyncDispatcher.m
+++ b/ActiveSync/SOGoActiveSyncDispatcher.m
@@ -114,6 +114,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #import <GDLContentStore/GCSChannelManager.h>
 #import <GDLContentStore/GCSFolderManager.h>
 
+#include <signal.h>
 #include <unistd.h>
 
 #ifdef HAVE_OPENSSL